Gear hardening machine



Jan. 15, 1952 s. o. GRIDLEY GEAR HARDENING MACHINE 3 Sheets-Sheet 1 Filed Jan. 15, 1947 INVENTOR o ge o Gpidley ATTORNEYS.

Jan. 15, 1952 e. o. GRIDLEY GEAR HARDENING MACHINE I5 Sheets-Sheet 2 Filed Jan. 15, 1947 INVENTOR O. GPidley ATTORNEYS Jan. 15, 1952 G. o. GRIDLEY GEAR HARDENING MACHINE 3 Sheets-Sheet (5 Filed Jan. 15, 1947 ATTORNEY.

Patented Jan. 15, 1952 UNITED STATES PATENT OFFICE GEAR HARDENING MACHINE George 0. Gridley, Berlin, Conn., assignor to The New Britain Machine Company, New Britain, Conn., a corporation of Connecticut Application January 15, 1947, Serial No. 722,169

4 Claims.

My invention relates to a heat-treating device and in particular to an improved induction- .hardening device for treating the teeth of a mi.

It is an object of the invention to provide an improved means for heat-treating gear teeth.

.It is another object to provide an improved gear-tooth heat-treating device in which a large number of types and sizes of gears may be readily accommodated.

It is a further object to provide a device of the character indicated in which the heat-treatin time can be kept to a minimum.

Other objects and various further features of the invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings:

Fig. 1 is a side view of a heat-treating device incorporating features of the invention, with some parts omitted for purposes of clarity;

.Fig. 1A is a fragmentary view of certain locating parts of Fig. 1, shown in an alternate selected position as compared with Fig. 1;

Fig. 2 is a plan'view of the device of Fig. 1;

Fig. 3is-a right end view of the device of Fig. 2, as seen from substantially the plane 3--3 of Fig. 2;

Fig. 4 is a fragmentary plan view of the device of Fig. 1, showing the relationship of parts for a diflerent part of the cycle of operations than is shown in Fig. 2; and

Fig. 5 is a generally schematic diagram illustrating cooperation between control functions for the apparatus of Fig. 1.

Broadly speaking, my invention contemplates a heat-treating device in which the heat-treating element is fixed and in which suitable positioning means are employed for properly locating gear teeth for treatment by said element in quick and efficient succession. The time-consumed for the complete cycle of operation (1. e. time between a treatment of one tooth and a corresponding treatment of the next succeeding tooth) is held to a minimum by a novel mechanism which not only secures accurate and positive placement of each tooth to be treated but combines a toothindexing function with the tooth-placement function. In the specific form to be described, a quenching operation may be initiated prior to termination of the heating process and prior to withdrawal of the gear from the heat-treating element-the quenching continuing during withdrawal and indexing, and, ifneed be, during the positioning of the next tooth for treatment by the heattreating element.

Referring to the drawings, my invention is shown in application to a heat-treating device employing a heat-treating element I 0 fixedly located withrespect to a frame member H. The

heat-treating means I0 is preferably an inductor forming part of a high-frequency inductiontype heat-treating equipment. In the form shown, the inductor I0 is essentially a single loop defined by two lateral. branches I2-I3, which may be suitably formed as with projections HI5 to fit between adjacent teeth I6l1l8 of a gear 19 to be heat-treated. It will be clear that by forming the sides l2-l3 of the loop ID with projections I4 it is possible to concentrate the eddy currents causing the heating process in the regions of greatest wear and stress on the tooth I1. Upon suitable quenching of the heated tooth H, as by a water spray or quenching head 20 having a plurality of longitudinally directed jets or apertures 2|, it is possible to produce a desired hardness for a desired depth of penetration along the side walls or faces of the tooth 11 without rendering the central structure of the tooth l1 hard or brittle.

In accordance with the invention, I provide novel means for the automatic placement of succeeding gear teeth (such as the teeth l1, it, etc.) in proper position between the branches l2 and I3 of the heat-treating element II). To assist in this placement, the gear l9 may be mounted upon a spindle 22 forming a revoluble part of a work-supporting means 23, which is preferably longitudinally slidable with respect to the frame I I. In the form shown, the work-positioning means 23 includes a side arm portion 24 having longitudinally extending ways 25 for slidably receiving a bracket 26. The bracket 26 carries a transversely extending arm 21. By means of a longitudinal slot 28 in the bracket 26, and by means of a bolt 29 receivable in one of a number of tapped holes 30 in the ways 25, the bracket 28 may be longitudinally adjusted with respect to the arm 24 to accommodate various diameter gears It, as will later be clear. An adjustable stop 3| determines the limiting retracting (leftward in the sense of Figs. 1, 2, and 4) operation of the slldable gear-support means 23, as by abutting engagement with the end of the arm 24 (see Fig. 4).

Longitudinal displacement of the sliding gearsupport means 23 and therefore of the gear I!) carried thereby is directly actuated and controlled by a. hydraulic cylinder 32 having a double-acting piston therein; that is, the piston will be forced to actuate its stem 33 to the right (in the sense of Figs. 1. 2 and 4) upon application of hydraulic pressures through a pipe connection 34, and to the left upon application of similar pressures through the pipe 35.

In accordance with a feature of the invention, the end of the stem 33 of the hydraulic piston carries a head member 36 which is preferably generally cylindrical and which is permitted freedom to slide longitudinally and rotatably within a suitable support 31, which may and preferably is fixed to the frame I i of the machine. The end of the head 35 carries work-engaging means which in the form shown comprises two longitudinally projecting elements 38-39 suitably formed and disposed for simultaneous engagement with the same two adjacent teeth 4i-4i of the gear 19 when oriented in a first sense (the sense shown in Figs. 1, 2, and 3). When oriented in a transverse sense (see Fig. 1A) the individual projecting portions 38-39 of the head 36 will each serve to fit between two different sets of adjacent teeth 42-43 and 4344, respectively, of another type gear 45 to be treated. It is clear that the alternatives for angularly positioning the head 35 make possible an adaptation of the device either to a gear 19 having an odd number of teeth or to a gear 45 having an even number of teeth. Suitable key means operating between the head 36 and its support El may be employed to lock the head 35 against angular displacement once a selected orientation of the tooth-engaging portions 38-39 has been set up. In the form shown, this key means includes a member 45 threadedly receivable in the head support 37 and having a small projection 41 for engagement with one of a plurality of key ways or splines 43 formed in the periphery of the head 35.

The head 36 may be secured to the stem 33 by a threaded engagement which is longitudinally located by means of an enlarged nut 49 abutting the back end of the head 36. It will be clear that the nut 49 may serve as a stop when it abuts the head support 3-? to limit the forward or positioning displacement of the work-engaging head 36. For a purpose which will later be clear, the back side of the nut 49 longitudinally clears the bracket arm 21 by an amount slightly in excess of the amount by which the projections 38--39 radially enter between adjacent teeth 49-4! of the gear [9. It will be recalled that this adjustment may be made by a suitable placement of the bracket 25 and of its securing bolt 29.

In accordance with another feature of the invention, the head support 3'? on the frame ll to which it is secured pivotally supports a pawl member 53 on a projecting bracket 5 l. The pawl member may carry a tooth-engaging finger 52 in order to provide an adjustable extension of the pawl. The pawl finger 52 preferably engages a tooth at a time on the gear 9 at points displaced from the longitudinally extending plane in which the spindle 22 (for supporting the gear It) is displaceable. In order to assure ratcheting engagement of the pawl finger 52 with succeeding teeth of the gear 89 resilient means such as a spring 53 may. urge constantly against the pawl member 50.

In order that a mechanical function of the elements thus far described may be understood, I shall describe this cooperative functioning. Fig. 2 shows a gear [9 in a forward position with the tooth ll located between the heat-treating members l4 and IS in position for application of the heating process. The forward position is located and positively determined by abutment of the nut 49 with the head support 3? when the hydraulic piston has been furthest displaced to the right, as by application of hydraulic pressures through the pipe 34. In this forward position the pawl finger 52 urged by the spring 53 rests in contact with a corner or side face of a tooth 53' of the gear l9. It will be noted that for the gear i9 shown, there are five gear teeth between the head projection 38 and the pawl finger 52 (namely the gear teeth 4| 53).

Retraction of the tooth I! from its position between the heat-treating members l4-I5 is accomplished by reversing the application of the hydraulic pressures from the pipe 34 to the pipe 35, resulting in a retracting withdrawal of the stem member 33 and of the head 36 and nut 49. During the first part of this retraction, namely, the period until the nut 49 engages the bracket arm 21, there is no withdrawal of the gear I9, but there is a complete retraction of the projections 38-39 from their position between the adjacent gear teeth it-4|. Upon abutment of the nut 49 with the bracket arm 27, the bracket 26, the arm 24, and the gear-supporting means 23, which are all secured together, are retracted until the arm 24 abuts the adjustable stop 31. It will be clear that this second part of the retracting process may result in a full withdrawal of the tooth ll from between the heat-treating members l4--l5 and that accompanying this withdrawal the nose of the pawl finger 52 engages the gear tooth 54 to impart a turning moment to the gear I9, thereby indexing the same one tooth by the time the arm 24 abuts the back stop 3| (see Fig. 4).

After accomplishment of this indexing function, it will be clear that the tooth I8 is in alinement with the space between the heat-treating members 14 and I5 and that an application of hydraulic pressure to the back of the piston (i. e. through the pipe 34) will cause the projections 33-39 first to engage between the next pair of adjacent teeth 5540 so as positively to locate the tooth IS (in an angular sense about the axis of the gear l9) before pushing the gear [9 and its slidable supporting means 23 forward. Limiting forward displacement is determined by abutment of the nut 49 against the head support 31. After accomplishment of the heat-treating function upon the tooth iii, the described cycle of operations may be repeated in order to index succeeding teeth 5t, 5?, etc. into position for treatment.

To appreciate how a desired timing sequence may be assured for the described operations and for the heat-treating operations, reference may be had to the schematic diagram of Fig. 5, in which an electric motor 58, which is preferably synchronous, initiates the timing sequences. The timing motor 58 may be supplied from a suitable power source 59 and may drive timing switches 60, 5|, 62 through suitable reduction gearing 64. In the form shown, the timing switches 60, 61, 62 are all ganged to operate definite control elements for given fractions of a single revolution of the drive shaft 65 for the switches. The switch 69 is shown to control an electric relay 66 for ac tuation of a solenoid 6! controlling operation of a valve 68, which may govern the flow of Water or other coolant employed for quenching purposes. The switch 6| is shown connected for operation of a relay 59 for controlling the on-oroff operation of the induction-heating equipment supplying high-frequency energy to the heating element It). The switch 62 is shown connected for operation of a work-positioning relay 19 to actuate a solenoid II, which selectably positions a hydraulic valve 12 for application of hydraulic pressures either to the pipe 34 for forward positioning of the gear-supporting means 23 or to the line 35 for retraction of the same. In Fig. 5, the direction arrows in the lines 34--35 indicate the direction of flow of hydraulic fluid for a forward positioning of the gear-supporting means 13, the exhaust flow returning in the line 34 for dttchargeto a sump through the line 13. It will b'e' clear that all relays and solenoids, as well as the motor 58, may be supplied as shown by the same power source 59.

A preferred sequence for operation of the switches 60, 6|, 62 and, therefore, for operation of the entire heat-treating device will be described, commencing with the instant shown in Fig. 5, at which time the switch 60 is about to break contact so as to terminate the quenching operation. At this time, the gear l9 and its positioning parts are in the relationship shown. in Fig. 4, that is, they are fully retracted. With the timing shaft 65 rotating clockwise, the switch 62 next makes contact to operate the work-positioning relay H1, thereby calling for an application of hydraulic pressures to the line 34, and in turn causing forward projection of the gear I9, to position a tooth I! for heating. This forward-projecting operation occurs rapidly, so that the switch 6| may close shortly after closure of the switch 62. As soon as the switch 6| is closed, the relay 69 calls for the application of high-frequency energy for a length of time determined by the arcuate extent of the switch 6|. Preferably just before the switch 61 breaks contact, the switch 60 operates to initiate the quenching action. Once quenching is initiated, the switch 6! and the switch 62 break contact to call, respectively, for the cut-oil of high-frequency energy and for a retracting displacement of the gear I9. It will be recalled that this retracting displacement is accompanied by the indexing operation so that when the switches 60, 6|, 62 return to the position shown in Fig. 5, the next-succeeding untreated gear tooth I8 is in position for heattreating.

In accordance with another feature of the invention, I provide means whereby the entire automatic apparatus which has been described may be shut down when all teeth of a particular gear have been treated. In the form shown, this means includes a cam-controlled switch 14 which I may be secured to the frame ll of the machine. The cam comprises a projection 15 on a disc 16 carried by the gear-supporting spindle 22, and once for every revolution of the spindle 22 and hence of the gear l9 this projection 15 may engage a transversely slidable member 11, which in turn may operate the control arm 18 of the switch 14. By connecting the switch 14 in series with the power source 59 so as to interrupt the supply of power to the motor 58, it will be clear .1."

that the treatment of any one gear may be fully automatic.

It will be understood that I have described a novel and relatively simple mechanism for quickly and effectively heat-treating gears of a wide range of sizes and types. Spiral gears may be accommodated by properly inclining the head 36 and its work engaging projections 38-39 and by suitably repositioning (as by inclining) the heattreating members I i-I5. The manner in which indexing, quenching, and retracting operations are made to coincide results in a maximum reduction of the time required to heat-treat each tooth and the automatic shut-off mechanism permits a gear once set up for treatment to be left for unattended processing.

While I have described my invention in detail for the preferred form shown, it will be understood that modifications may be made within the scope of the invention as defined in the claims which follow.

I claim:

1. In a heat-treating device of the character indicated, a frame, gear-supporting means longitudinally slidable with respect to said frame, work-positioning means longitudinally slidable with respect to said frame and including a part for direct longitudinal driving engagement with a tooth of a gear supported by said gear-supporting means, whereby said part may drive a gear into predetermined longitudinal and angular relationship with a heating means, lost-motion means directly coupling said gear-supporting means and said work-positioning means in a retracting stroke and after said part is retracted out of engagement with the gear, said workpositioning means and said gear-supporting means being in direct driving relation upon said coupling of said lost-motion means, and pawl means carried by said frame for ratcheting engagement with the teeth of the gear, whereby the gear may be positively indexed upon a longitudinal movement of said work-positioning means.

2. A device according to claim 1, in which double-acting fluid-pressure actuating means is provided in direct advancing and retracting driving relation with said work-positioning means, whereby a gear carried by said work-supporting means may be positively and assuredly positioned for treatment by said heat-treating means and positively and assuredly retracted from said heat-treating means after treatment.

3. In a, heat-treating device, a frame including an element to fit between adjacent teeth of a gear to be treated, work-positioning means longitudinally slidable with respect to said frame and including a part for direct longitudinal driving engagement with a tooth of the gear, gearsupporting means longitudinally slidable with respect to said frame and including a spindle for mounting a gear, whereby said part may drive a gear into predetermined longitudinal and angular relationship with a heating means, the spindle axis and said heat-treating element and the displacement axis of the said part all lying in substantially a common longitudinally extending plane, lost-motion means directly coupling said gear-supporting means and said work-positioning means in a retracting stroke and after said part is retracted out of engagement with the gear, said work-positioning means and said gear-supporting means being in direct driving relation upon said coupling of said lost-motion means, and pawl means carried by said frame and offset from said plane for ratcheting engagement with teeth of the gear, whereby after said part has been disengaged from the gear said pawl means may be effective to positively index the gear substantially coincidentally with positive disengagement of the gear from said heattreating element.

4. A heat-treating device according to claim 3, in which said work-positioning means includes electrically controlled reciprocating driving means, cam means mounted for rotation with said spindle, and an electric switch mounted on a non-rotating part of said device to cooperate with said cam means to open the control circuit of said driving means upon completion of one revolution of the gear about its support on said gear-supporting means.

GEORGE 0. GRIDLEY.

(References on following page) 7 8 REFERENCES CITED Number Name Date The following references are of record in the 2,264,752 Greene 1941 file of t t 2, 7 ,005 Shorter Feb. 24, 1942 2,304,148 Carlsen Dec. 8, 1942 UNITED STATES PATENTS 5 2,361,995 Curtis N 7, 1944 Number Name Date 2,398,085 Denneen et a1 Apr. 9, 1946 1,768,159 Shorter et a1 June 24, 1930 ,428,303 Wood Sept. 30, 1947 2,180,038 Denneen et a1 Nov. 14, 1939 

